Arsenic is a compound that occurs naturally in very low concentrations. arsenic blood concentrations in healthy adults are normally distributed, with mean =3.2μ=3.2 micrograms per deciliter /dl)(μg/dl) and standard deviation =1.5 /dlσ=1.5 μg/dl . what is the range of arsenic blood concentrations corresponding to the middle 90% of healthy adults?

range of arsenic blood concentrations: 0.725 μg/dl  - 5.675 μg/dl

Step-by-step explanation:

Data

μ=3.2 μg/dl

σ=1.5 μg/dl

Let's call x1 the maximum arsenic blood concentrations and x2 the minimum concentration for the range corresponding to the middle 90% of healthy adults. To get x1 is necessary to find the x for that the area below the standard normal distribution is 0.45. In table attached it can be seen that this area correspond to Z = 1.65. Using Z definition, x1 can be isolated

Z = (x1-μ)/σ = 1.65

x1 = 1.65*σ + μ

x1 = 1.65*1.5 + 3.2

x1 = 5.675 μg/dl

Knowing that normal distribution is symmetrical respect to 0, then the area between Z = -1.65 and Z = 0 is also 0.45. So, x2 is computed as

Z = (x2-μ)/σ = -1.65

x2 = -1.65*σ + μ

x2 = -1.65*1.5 + 3.2

x2 = 0.725 μg/dl

to plot points   for x just start at the origin (middle) and go to the left however many times it say(if the number is a positive) if the number is a negative then go right however many times it says if it is 0 go nowhere

now keep you pencil there and go up however many times it says on y(if it is positive) if it is negative then go down however many times it says. if it says 0 go nowhere.

you have just plotted a point! now when you finish plotting all of them connect them with a ruler

plot each point as (-3, 7), (0,4), (3,1), (8,-4)   in the parenthesis on the left of the comma is x and the right is y.

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i hope this answer you! if you have any further questions or concerns, feel free to ask! : )

step-by-step explanation:

mark brainliest!